Series 7 of Spooks began airing on 27 October 2008 for an eight episode run. Peter Firth returned as Harry Pearce, along with Alex Lanipekun as Ben Kaplan, Hugh Simon as Malcolm Wynn-Jones and Gemma Jones as Connie James.
The first episode saw central character Adam Carter (portrayed by Rupert Penry Jones) die in a car explosion. It also saw the return of Ros Myers (played by Hermione Norris) and Jo Portman (Miranda Raison) as both of their fates were uncertain at the end of series 6. Richard Armitage joined the cast as Lucas North, an agent who has been held in a Russian prison for the past eight years. Following Adam's death, Ros was made the section leader and Lucas replaced her as a Senior Case officer.In an interview on BBC Radio Five Live, Peter Firth intimated that Harry and Ruth might well be reunited, though this proved to be a red herring with regard to Series 7. He also stated that he was unaware of any potential plans for an eighth series, "like all TV, it depends on ratings...we'll have a good idea after (tonight's episode)". Spooks attracted an average audience of 5.9 million, with roughly 825,000 viewers watching the 10:30 pm showing of Episode Two on BBC Three. The second episode when shown the following day on BBC One drew in 5.6 million (a 22% audience share). The third episode when shown on BBC One on 3 November had an average audience of 5.6 million, once more claiming a 22% audience share. On November 10th, Spooks drew 5.2 million viewers, with a 21% audience share, down from the previous week. On , it drew an average audience of 4.9 million receiving a 20% share, however, it was broadcast against I'm A Celebrity Get Me Out Of Here! in the same time slot. The following week, Episode Six averaged 5.4 million, with a 22% share. Interestingly, the penultimate episode of the series which was broadcast on BBC Three at 10:30 pm managed to bring in 1 million viewers, being one of the most watched multi-channel shows of the night, easily beating Sky1's return of 24 which managed just under 400,000 viewers.
The series 8 recommission press release stated there would be a twist in the final episode of series 7. In this episode, a nuclear bomb is set to explode, triggered by a Russian sleeper agent who was part of Operation Tiresias. As Parliament and the Royal Family are evacuated, the nuclear threat to London is eliminated when Ros and Lucas are able to turn Connie James and elude an FSB kill squad. Connie was killed defusing the bomb by its conventional explosives. Seconds before the bomb exploded, Connie revealed that it had not been Harry who sold Lucas North out to the Russians as Lucas had always believed but rather herself. The episode concluded with Harry, conscious but with his mouth taped shut, in the boot of a car being zipped up in a body bag by Viktor Sarkisian, head of the FSB's London station.